/**
 * Copyright (c) 2009, Christian Schneider
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  - Neither the names of the authors nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package com.ruinwesen.patchdownloader.swing.misc;

import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.WeakHashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.ruinwesen.patchdownloader.PatchDownloader;
import com.ruinwesen.patchdownloader.indexer.Doc;
import com.ruinwesen.patchdownloader.patch.PatchMetadata;
import com.ruinwesen.patchdownloader.repository.LocalRepository;
import com.ruinwesen.patchdownloader.repository.StoredPatch;
import com.ruinwesen.patchdownloader.repository.StoredPatch.JarFilePatch;

public class MetadataCache {

    private static Log log = LogFactory.getLog(MetadataCache.class);
    
    private Map<Integer, PatchMetadata> metadataCache = 
        new WeakHashMap<Integer, PatchMetadata>();

    public void clear() {
        metadataCache.clear();
    }
    
    public PatchMetadata getMetadata(Doc doc, boolean locate) {
        PatchMetadata metadata = metadataCache.get(doc.id());
        if (metadata != null || !locate) {
            return metadata;
        }
        
        LocalRepository repository = 
            PatchDownloader.getSharedInstance().getRemoteRepositoryBackup();
        
        File patchFile = new File(repository.getBaseDir(), doc.path());
        
        try {
            JarFilePatch jar = new StoredPatch.JarFilePatch(patchFile); 
            metadata = jar.getMetadata();
            metadataCache.put(doc.id(), metadata);
        } catch (IOException ex) {
            if (log.isDebugEnabled()) {
                log.debug("could not read metadata for patch:"+patchFile.getAbsolutePath(),ex);
            }
            return null;
        }
        return metadata;
    }
    
}
